1. Field of the Invention
The present invention is used in the field of office machines such as typewriters and similar machines, wherein an escapement mechanism cooperates with a carriage rack to permit the incremental advancement of the carriage. Means are provided for disengaging the escapement mechanism from the carriage rack to prevent damage to the mechanism and/or rack during certain conditions such as transport of the typewriter, and for automatically engaging the escapement mechanism with the carriage rack when carriage restraining means are removed from the typewriter.
2. Description of the Prior Art
Relevant prior art includes the typewriter escapement disengagement and escapement mechanism illustrated in FIG. 4 of the drawing and described more fully hereafter. A typewriter escapement disengagement and engagement mechanism substantially similar to that disclosed in FIG. 4 of the drawing is used in a typewriter sold by SCM Corporation under the trademark, "Sterling". The principal distinction between the mechanism shown in FIG. 4 and the present invention is that the prior art engagement mechanism shown in FIG. 4 requires a manual operation to cause the engagement of the escapement mechanism with the carriage rack when the carriage restraining means is removed, whereas the subject typewriter escapement disengagement and engagement mechanism includes means whereby the escapement is automatically engaged when the carriage restraining means is removed.
U.S. Pat. No. 1,715,428 to Rose discloses a mechanism whereby the escapement mechanism is disengaged from the carriage rack during transport of the typewriter, and thereafter automatically engaged with the carriage rack when the carriage restraining means, i.e. the typewriter carrying case covers, is lifted. However, the mechanism disclosed in the Rose patent for achieving this function differs substantially from the mechanism which is the subject matter of the present invention.